a. Field of the Invention
The invention relates to a method for cutting a tempered glass and a preparatory tempered glass structure for a cutting treatment.
b. Description of the Related Art
Generally, conventional methods for strengthening glass mainly include a heat strengthening treatment or a chemically strengthening treatment. For example, in a typical chemically strengthening treatment such as an ion exchange glass strengthening treatment, a glass substrate is submersed in a bath containing a potassium salt. This causes sodium ions on the glass surface to be replaced by potassium ions from the bath solution. Under the circumstance, a thin compression stress layer is formed on a skin layer of the glass substrate. As shown in FIG. 1A and FIG. 1B, a tensile stress TS is formed correspondingly inside a tempered glass 100 to compensate the compression stress of a compression stress layer DOL. Compared FIG. 1A with FIG. 1B, when the compression stress layer DOL becomes thicker (layer thickness in FIG. 1B is larger then that in FIG. 1A), the strength of the tempered glass 100 becomes greater and the tensile stress TS inside the tempered glass 100 also becomes greater. Hence, as the tensile stress TS is increased to a considerable extent, the tempered glass 100 being cut is liable to irregularly split due to the tensile stress TS. This may result in extremely low production yield.